Evaluation of low-impact modular housing using energy optimization and life cycle analysis

Abstract

This paper presents life cycle analysis of the container-based single-family housing and combines energy analysis and optimization, life cycle assessment and life cycle costing. The proposed models include the container code (CC), designed to Canadian national building code as reference model, and an improved container (IC) incorporating passive solar technologies. Utilizing passive design strategies results in approximately 79% reduction in annual operational energy consumption for the improved case. The life cycle assessment considers the total energy use and global warming potential over 60-year lifespan. Three life cycle phases are considered: pre-use, use and operation, and end of life. As a result of envelope upgrade, the IC offers 77% reduction in life cycle energy use and global warming potential (GWP) than the CC. However, the envelope upgrade requiring greater energy intensity through industrial processing of additional building materials led to higher environmental impact, approximately 65,370 kWh of embodied energy and 20 t of CO2 eq of GWP embodied carbon emissions for the improved container at pre-use phase. In terms of life cycle cost, IC shows less than 10% total cost savings as compared to CC. This study, however, proves that integrating passive solar design techniques in building not only results in reduced energy consumption but rather translates to reduction in life cycle environmental impacts and life cycle cost building systems, which is, in this case, a modular container housing.